Dolly equipped with loading-unloading scissor hoist

ABSTRACT

This invention relates to the hoist means employing the principle of the scissor action between a pair of the structural frames pivotably coupled to one another. The scissor hoist of the present invention employs either a combination of a pair of the structural frames of two different lengths wherein one extremity of the first structural frame with the other extremity resting on the floor or the ground is pivotably connected to the second structural frame intermediate one extremity raised to midair and the other extremity resting on the floor or the ground, which combination includes the mechanical or hydraulic means for creating the scissor movement between said two structural frames and the means for securing the hoist cable or chain to said one extremity of said second structural frame, or another combination including another pair of the structural frames pivotably connected to one another by the hinge joint disposed intermediate the one extremities raised to mid-air and the other extremities resting on the floor or the ground of said two structural frames, which combination includes the mechanical or hydraulic means for creating the scissor movement between said two structural frames and the means for securing the hoist cable or chain to a horizontal structural member secured to said pair of the structural frames at said hinge joint; whereby the raising and lowering movement of said horizontal structural member resulting from the scissor movement between said two structural frames raises and lowers the objects.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a means for hoisting a heavy object from the floor or the ground and loading it onto the platform of a dolly or trailer or flat car.

Another object of the present invention is to provide said hoisting and loading means which is integrally incorporated into the construction of the dolly or trailer or flat car.

A further object of the present invention is to provide said hoisting and loading means that is compact and simple in the construction and operation.

Still another object of the present invention is to provide a mobile hoist means for lifting the heavy objects in the field.

Still a further object of the present invention is to provide a hoist means that relies directly on the scissor movement between two structural frames coupled to one another in a pivoting relationship.

These and other objects of the present invention will become clear as the description of the present invention proceeds. The present invention may be described with a great clarity and specificity by referring to the following figures:

FIG. 1 illustrates an elevation view of a scissor hoist incorporated into the construction of a dolly or trailer or flat car.

FIG. 2 illustrates the plan view of the scissor hoist incorporated into the construction of a dolly or trailer or flat car as shown in FIG. 1.

FIG. 3 illustrates the scissor hoist shown in FIGS. 1 and 2 which is at the maximum hoisted position.

FIG. 4 illustrates the scissor hoist shown in FIGS. 1 and 2 that is at the stowed-away position wherein it is used as the handle of the dolly.

FIG. 5 illustrates the scissor hoist of the same construction and function as that of FIGS. 1 and 2 incorporated into the construction of a dolly having a platform equiped with a scissor lift.

FIG. 6 illustrates another scissor lift for hoisting the heavy objects in the field that can be used as a transporting vehicle as well.

In FIG. 1, there is shown an elevation view of a dolly 1 equipped with a scissor hoist 2, which combination is constructed in accordance with the principles of the present invention. The dolly 1 equipped with a scissor hoist comprises a platform or dolly frame 3 including four wheels 4,5, etc. The scissor hoist comprises a first frame 6 including a first long elongated member and a second long elongated member rigidly connected to one another by a cross member. The openextremity 7 of the first frame 6 is pivotably connected to the platform or dolly frame 3 near the first and second corners of the platform or dolly frame wherein the first frame 6 is pivotable about a first common pivoting axis. In the particular embodiment shown in FIG. 1, the first common pivoting axis coincides with the axis of the axle 8 rotatably supporting the wheels 5, etc. The closed-extremity 9 of the first frame 6 includes a cross member 10 rigidly affixed to the first and second long elongated members, wherein the means 11 such as a hook for securing an object to be hoisted depends from the cross member 10. The scissor hoist 2 further includes a second frame 12 comprising a first short elongated member and a second short elongated member. One extremity of the first short elongated member is pivotably connected to the first long elongated member intermediate one extremity pivotably connected to the platform or dolly frame and the other extremity rigidly connected to the cross member, while the other extremity of the first short elongated member includes a foot plate 13 pivotably connected thereto. One extremity of the second short elongated member is pivotably connected to the second long elongated member intermediate one extremity pivotably connected to the platform or dolly frame and the other extremity rigidly connected to the cross member, while the other extremity of the second short eleongated member includes a foot 14 pivotably connected thereto. The one extremity 16 of the second frame 12 included in the scissor hoist is pivotable about a second common pivoting axis substantially parallel to the first common pivoting axis, while the other extremity 15 of the second frame 12 including a pair of foot plates 13 and 14 rests on a floor or the ground. The hinge joints 17 and 18 pivotably connecting the first frame 6 and the second frame 12 defines the second common pivoting axis in the scissor movement of the first frame 6 and the second frame 12 about the second common pivoting axis. The scissor hoist 2 includes a pair of linear actuators 19 and 20 wherein one extremity of each of the two linear actuators 19 and 20 is pivotably anchored to the first and second long elongated members included in the first frame, respectively, and the other extremity of each of the two linear actuators 19 and 20 is pivotably anchored to the first and second short elongated members included in the second frame 12. The action of the two linear actuators 19 and 20 provides the scissor movement of the first frame 6 and the second frame 12 about the second common pivoting axis defined by the central axis of the hinge joints 17 and 19. The dolly 1 includes the means 21 for removally anchoring the foot plates 13 and 14, which is used to stow away the scissor hoist 2 in a position where the cross member included in the first frame of the scissor hoist serves as a handle for the dolly.

In FIG. 2 there is shown a plan view of the scissor hoist 2 incorporated into the construction of the dolly 1 as shown in FIG. 1. The first frame 6 included in the scissor hoist 2 comprises a a first and a second long elongated members 22 and 23 rigidly connected to one another by the cross member 10 at their upper extremities, while their lower extremities are pivotably anchored to the axle 8 rigidly secured to the platform or dolly frame 3 of the dolly 1. The cross member 10 supports slidably or affixedly the element 26 from which the hoist cable or chain with the hook 11 depends. The second frame 12 comprises a pair of a first and a second short elongated members 24 and 25 including the foot plates 13 and 14 at their lower extremities, which foot plates are pivotably connected to the lower extremities of the short elongated members 24 and 25, respectively. The upper extremities of the short elongated members 24 and 25 are pivotably connected to the long elongated members 22 and 23 included in the first frame 6 by means of the hinge joints 17 and 18 disposed intermediate the upper and lower extremities of the long elongated members 22 and 23. The pair of the linear actuators 19 and 20 with one extremities pivotably anchored to the pair of the long elongated members included in the first frame 6 and the other extremities pivotably anchored to the pair of the short elongated members included in second frame 12 provides the power required to create the scissor movement therebetween.

With the construction of the scissor hoist 2 integrated into the structure of the dolly 1 as shown in FIGS. 1 and 2, the scissor hoist 2 operates in the following principles: The heavy object to be loaded onto the platform 3 of the dolly 1 is located directly under the hoist hook 11 lowered to the lowest possible position by opening up the scissor movement between the pair of the structural frames included in the scissor hoist 2 and is secured to the hoist hook 11, which object is hoisted by closing the scissor movement between the pair of the structural frames included in the scissor hoist 2 which movement raises the upper extremity 9 of the first frame 6 and places the hoisted object directly above the platform 3 of the dolly 1 as the linear actuators 19 and 20 extend. The scissor hoist 2 lowered to the pick-up position is shown in FIG. 1. The scissor hoist 2 with the hoisted object lifted and placed directly above the platform of the dolly is shown in FIG. 3. In the process of hoisting an object initially located directly under the hoist hook lowered to the lowest possible position, the hoisted object becomes shifted toward to the dolly and, at the same time, the dolly rolls toward to the object being hoisted. Once the object is fully hoisted and placed directly above the platform of the dolly, the object can be lowered onto the platform by unrolling the hoist cable or chain in a controlled way or by lifting the platform of the dolly if it is equiped with a scissor lift as shown in FIG. 5. Once the object is landed on top of the platform of the dolly and the scissor hoist is free of a burden, the scissor hoist 2 can be stowed away in a position as shown in FIG. 4 wherein the foot plates 13 and 14 are secured by the means 21 and the scissor hoist 2 is used as the handle of the dolly 1.

In FIG. 5 there is shown the scissor hoist 27 incorporated into the construction of the dolly 28 having a platform 30 equiped with a scissor lift 29, wherein the scissor hoist 27 has the same construction and function as that shown in FIGS. 1 and 2. The dolly 28 equiped with the scissor hoist 27 and the scissor lift 29 has the total capability to load and unload the heavy objects without depending on any other hoisting or lifting device.

It should be understood that the foot plates pivotably connected to the lower extremity of the second frame included in the scissor hoist shown in FIGS. 1 and 2 may be replaced with a pair of wheels if the specific working environment demands such a modification. The foot plates may be designed in such a way that they are clear out of the way of the wheels included in the dolly or that they are in the way of the wheels of the dolly and serves as the wheel stop once the dolly wheels come to contact with the foot plates. The linear actuators providing the power to the scissor hoist may be the hydraulic or pneumatic cylinders driven by a power source or by the manual power, or they may be the mechanical devices such as the jack screws or compound pulley systems or the winches or the lever or gear systems. The illustrative embodiments shown in FIGS. 1, 2 and 3 employ the hydraulic cylinders, which combination is employed for the sole purpose of illustrating the principles of the present invention without ruling out the use of other type of the linear actuators well known in the art of the mechanical actuating technology.

In FIG. 6 there is shown another scissor hoist 31, which is a mobile type designed for hoisting and transporting the heavy objects in the field. The scissor hoist 31 comprises the first structural frame 32 and the second structural frame 33 pivotably connected to one another by the hinge joints 34 and 35 disposed intermediate two extremities of said pair of the structural frames. The horizontal structural member 36 is simultaneously supported by both of the structural frames 32 and 33 at the points where the hinge joints 34 and 35 are disposed. The lower ends of the structural frames 32 and 33 include each of the pairs of the steerable wheels 38 and 39; 40 and 41, respectively. In the entire range of the scissor movement between the pair of the structural frames included in the scissor hoist 31, one structural frame is substantially the mirror image of the other structural frame. The structural members 42 and 43; 44 and 45 respectively included in the first structural frame 32 and the second structural frame 33 are slightly curved in one direction on the plane of the scissor movement in the lower portion in order to provide a greater clearance thereunder, while the upper portion of said structural members are curved in the opposite direction in order to provide a suitable arrangement for installing the hydraulic cylinders 46, 47, 48 and 49 wherein one extremity of each of said hydraulic cylinder is pivotably anchored to the upper extremity of each of said structural members, while the other extremity of each of said hydraulic cylinders is pivotably anchored to each of said structural members intermediate the lower extremity equiped with said steerable wheels and the hinge joint; whereby, the extension of said hydraulic cylinders creates the closing scissor movement between two structural frames included in the scissor hoist raising the horizontal structural member to which the hoist cable or chain is secured, while the retraction of said hydraulic cylinders creates the opening scissor movement lowering the heavy object secured to the hoist cable or chain depending from the horizontal structural member. During the scissor movement, at least one pair of the steerable wheels included in one structural frame must be steered parallel to the plane of the scissor movement in order to facilitate the extension or retraction of said hydraulic cylinders. The steerable wheels included in the scissor hoist 31 may be motorized to provide the self-propelling capacity to the scissor hoist 31 whereby it can be used as a hoiting means as well as a transporting means.

While the principles of the present invention have now been made clear by the illustrated embodiments, there will be immediately obvious to the skilled in the art many modifications of the structure, elements, proportions, arrangement and materials particularly adapted to the specific working environment and operating condition in the practice of the invention without departing from those principles. 

I claim:
 1. A dolly equipped with a loading-unloading scissor hoist comprising in combination:(a) a platform of rectangular shape including a plurality of wheels rollable on a floor or the ground; (b) a scissor hoist including;(1) a first long elongated member with one extremity pivotably connected to said platform near a first corner of said platform; (2) a second long elongated member disposed substantially parallel to said first long elongated member with one extremity pivotably connected to said platform near a second corner of said platform wherein said first and second long elongated members are pivotably about a first common pivoting axis; (3) a cross member rigidly connected to the other extremity of said first long elongated member opposite to said one extremity and connected to the other extremity of said second long elongated member opposite to said one extremity, said cross member including means for securing an object to be hoisted by said scissor hoist; (4) a first short elongated member with one extremity pivotably connected to said first long elongated member intermediate said one and the other extremity of said first long elongated member wherein said first short elongated member is pivotable about second common pivoting axis, said first short elongated member including a foot plate connected to the other extremity of said first short elongated member in a hinged relationship; (5) a second short elongated member disposed substantially parallel to said first short elongated member with one extremity pivotably connected to said second long elongated member intermediate said one and the other extremity of said second long elongated member wherein said second short elongated member is pivotable about said second common pivoting axis, said second short elongated member including a foot plate connected to the other extremity of said second short elongated member in a hinged relationship; (6) a first linear actuator providing a scissor movement of said first long elongated member and said first short elongated member substantially straddling said platform about said second common pivoting axis; (7) a second linear actuator providing a scissor movement of said second long elongated member and said second short elongated member substantially straddling said platform about said second common pivoting axis; and (8) a first means disposed near a third corner of said platform diagonally opposite to said second corner for removably anchoring said the other extremity of said first short elongated member, and a second means disposed near a fourth corner of said platform diagonally opposite to said first corner for removably anchoring said the other extremity of said second short elongated member;whereby, when said foot plates respectively connected to said the other extremities of said first and second short elongated members are placed on a floor or the ground, said scissor hoist is usable for hoisting an object from the floor or the ground in loading and for hoisting an object from said platform in unloading, and when said the other extremities of said first and second short elongated members are respectively anchored to said first and second means for removably anchoring, said cross member affixed to said first and second long elongated members is usable as a handle of said dolly.
 2. A dolly equipped with a loading-unloading scissor hoist comprising in combination:(a) a dolly frame of rectangular shape including a plurality of wheels rollable on a floor or the ground; (b) a scissor hoist including;(1) a first long elongated member with one extremity pivotably connected to said dolly frame near a first corner of said dolly frame; (2) a second long elongated member disposed substantially parallel to said first long elongated member with one extremity pivotably connected to said dolly frame near a second corner of said dolly frame wherein said first and second long elongated members are pivotable about a first common pivoting axis; (3) a cross member rigidly connected to the other extremity of said first long elongated member opposite to said one extremity and connected to the other extremity of said second long elongated member opposite to said one extremity, said cross member including means for securing an object to be hoisted by said scissor hoist; (4) a first short elongated member with one extremity pivotably connected to said first long elongated member intermediate said one and the other extremity of said first long elongated member wherein said first short elongated member is pivotable about second common pivoting axis, said first short elongated member including a foot plate connected to the other extremity of said first short elongated member in a hinged relationship; (5) a second short elongated member disposed substantially parallel to said first short elongated member with one extremity pivotably connected to said second long elongated member intermediate said one and the other extremity of said second long elongated member wherein said second short elongated member is pivotable about said second common pivoting axis, said second short elongated member including a foot plate connected to the other extremity of said second short elongated member in a hinged relationship; (6) a first linear actuator providing a scissor movement of said first long elongated member and said first short elongated member substantially straddling said dolly frame about said second common pivoting axis; (7) a second linear actuator providing a scissor movement of said second long elongated member and said second short elongated member substantially straddling said dolly frame about said second common pivoting axis; (8) a first means disposed near a third corner of said dolly frame diagonally opposite to said second corner for removably anchoring said the other extremity of said first short elongated member, and a second means disposed near a fourth corner of said dolly frame diagonally opposite to said first corner for removably anchoring said the other extremity of said second short elongated member; and (9) a platform equipped with a scissor lift and disposed on top of said dolly frame wherein said platform is raised and lowered by a scissor action of said scissor lift;whereby, when said foot plates respectively connected to said the other extremities of said first and second short elongated members are placed on a floor or the ground, said scissor hoist is usable for hoisting an object from the floor or the ground in loading and for hoisting an object from a dolly platform in unloading, and when said the other extremeties of said first and second short elongated members are respectively anchored to said first and second means for removably anchoring, said cross member affixed to said first and second long elongated members is usable as a handle of said dolly. 